Yarn guiding drum for winding machines



Jan. 24, 1961 H. WOLFF YARN GUIDING DRUM FOR WINDING MACHINES Filed July 29. 1957 W w 4 A5... vwasgf? jnitedi rates i atent YARN GUIDING DRUM FOR WINDING MACHINES Helmut Wollf, M. Gladhach, Germany, assignor to Walter Reiners, M. Gladhach, Germany Filed July 29, 1957, Ser. No. 674,829

Claims priority, application Germany Aug. 8, 1956 9 Claims. (Cl. 242-432) My invention relates to winding machines, particularly those for the winding of cross-wound yarn bodies, in which the yarn passes to the take-up spool over a rotating guiding drum which is provided with grooves for imparting to the oncoming yarn a to-and-fro movement along the take-up spool, and which drum has its peripheral surface engaged by the take-up spool in order to simultaneously drive the spool.

In such machines the shape and design of the yarn guiding grooves in the guiding drum is of decisive importance for reliable control of the yarn being wound. It has been found in practice that particular attention must be given to good guiding control of the traveling yarn at the reversing points, i.e. the right hand and left hand limit zones of the guiding groove. This requires a particular design of the guiding drum at these locations in order to secure reliable guiding of the yarn on the one hand and an exact as possible deposition of the yarn onto the spool being wound up.

It has already been proposed to design the reversing points of the guiding groove in such manner that the groove bottom is pulled up or raised as much as possible in order to make the yarn guiding distance slight, this distance being the spacing between the point where the yarn leaves the guiding edge of the drum groove and passes onto the take-up spool, and the point where the yarn enters onto the spool being wound. Such pulling up or shallowness of the bottom groove at the reversing points, however, has the disadvantage that, due to the reduction in groove depth at one of the most critical locations, the reliability of yarn control is considerably diminished. This manifests itself by the fact that the yarn may jump out of the guiding groove at higher winding speeds, and may result in faults such as loose loops.

It is an object of my invention to eliminate such de ficiencies of the yarn guiding drum.

To this end, and in accordince with my invention, the groove bottom is drawn up, ie the groove is made shallower, at a location which, with respect to the running direction of the drum, lies behind the reversing point of the reciprocating yarn movement.

According to a more specific and preferred feature of the invention, the design of the guiding groove at the shallow location is such that a yarn portion is guided, from the highest point of the groove bottom behind the reversing point to the running-on point of the yarn at the take-up spool, exactly or approximately through the outermost point of the reversing location.

The foregoing features are embodied in the coil winding device according to the invention illustrated by way of example on the drawing, in which Fig. 1 is a partial and sectional view of a yarn guiding drum and a spool being wound, the drum being shown in a position where the yarn passes through a reversing point of the guiding groove;

Fig. 2 is a similar illustration of the same components in a position where the yarn is placed upon the spool inc from the outermost point of the reversing location; and

Figs. 3 and 4 are front views of two types of yarnguiding drums and take-up spools.

According to Figs. 1 and 2, the yarn guiding drum 1 is mounted on a driven shaft 2 and is provided with a yarn guiding groove 5 which extends on the drum periphery along the drum over the axial extent of the spool 4 to be wound and which is closed upon itself so as to impart to the running yarn F a reciprocating movement as the yarn is being wound onto the spool 4. The guiding drum 1 is contacted by the take-up spool 4 and thus imparts to this spool the necessary winding movement which, since the shaft 2 is normally driven at constant speed, insures a constant peripheral speed of the yarn as it is being deposited onto the spool. The spool is commonly gravity suspended at its axis, by a pivot arm 40 free to oscillate about a support 41.

The guiding groove may be of a commonly known type in which the groove comprises a continuous groove 5 (Figs. 1 and 3 or 5 (Fig. 4). For further details of such devices, and other yarn reciprocating guide drums, reference may be made to the various patents describing them. In Fig. 3 the drum and take-up spool 4 are cylindrical. In Fig. 4 the drum 1 and take-up spool 4 are frustro-conical. The reversing locations are designated 6 in Fig. 3.

The guiding groove 5 of the drum 1 of Figs. 1 and 2 has reversing locations at 6 where the two groove portions interconnect. The groove bottom is denoted by 7. The location where the depth of the groove is least is denoted by 8, this shallowest location being situated behind the reversing location 6. Location 8 is also termed herein a peak portion in the groove bottom. The outermost guiding point at the reversing location 6 is denoted by 9. The running-on point of the yarn F, that is, the point where the yarn passes onto the body of yarn wound onto spool 4, is denoted by 10.

When the yarn F is being wound onto the spool 4 and is being simultaneously reciprocated along the spool by means of the groove 5, the tendency of the yarn F to jump out of the groove decreases with increase in depth of the groove. The yarn guiding reliability therefore is largest where the groove has its largest depth. Although it follows that the yarn control is best when the groove is given large depth, this is accompanied by the disadvantage that when the yarn leaves the groove at the groove edge it must extend a correspondingly larger distance without guidance by the groove before the yarn runs onto the spool. In other words, this free portion of the running yarn reduces the yarn guiding reliability, and the effect is in proportion to the length of the spacing between the point where the yarn passes out of the groove and the point where the yarn runs onto the spool. For that reason the depth of the groove cannot be indiscriminately increased in extent.- In order to secure an accurate deposition of the yarn F onto the spool 4 it is necessary to keep the spacing between the outermost point 9 of the reversing location 6 and the running-on point 10 of the yarn as small as possible. Such reduction of the just mentioned spacing requires tangential guidance of the yarn toward the spool.

The illustrated solution of the problem involves a compromise. It can be recognized from Fig. 1 that when the yarn travels onto the reversing location 6 almost the greatest depth of the guiding groove is reached and that shortly behind this location, where the transverse movement of the thread is caught, or retarded, and the return movement of yarn reciprocation commences, the depth of the groove is still so great that sliding of yarn F out of the groove 5 is improbable. This reliability of yarn control at the reversing location is still effective when the yarn, shortly before it jumps in the reverse direction, oc-

copies the instantaneous position illustrated by a broken line in Fig. 1.

It is apparent from Fig. 2 that at the moment when the incoming yarn runs onto the outermost end points of the reversing location; that is, when the yarn passes through the reversing location 6 and shortly after it leaves that location, the points 6 and move closer toward each other. That is, at the moment of operation just considered, the outermost guiding point of the reversing location 6 and the point 10 where the yarn runs onto the spool 4 come considerably closer to each other than is the case during the stage of operation shown in Fig. 1. By virtue of the slight spacing of points 9 and 10 an extremely accurate deposition of the yarn at the periphery of the spool is secured despite the slight depth of the groove.

In the claims the term behind the reversing point means the region to the right of reversing point 6 in Fig. 2. The term forward of the reversing point means the region to the left of reversing point 6 in Fig. 2.

Although in the preferred form of the invention the take-up spool rests upon and is directly turned by drum 1, it is possible to employ other drive means such as as a roller or gears. It is preferable in such cases to maintain close propinquity of the spool and drum, and the equality of peripheral speeds of the two.

Thus the invention achieves not only a greater yarn guiding reliability at the reversing locations of the reciprocating travel, but, by the periodical shortening of the distance between points 9 and 10, the threaded jumping-ofl of the yarn at the edges is simultaneously pre vented.

I claim:

1. In a coil winding machine having spool holder means including pivot means for rotatably holding a spool to be wound, the combination with said holder means of a rotatable guiding drum having an axis parallel to that of said pivot means and being, when in operation, peripherally engaged by the spool for driving the latter, said drum having in its peripheral surface a yarn guiding groove extending peripherally and axially of the drum and being closed upon itself and having two axially spaced reversing locations, for reciprocating the yarn along the spool as the yarn is being wound onto the spool by rotation of said drum, said guiding grove having in the regions before and behind the reversing locations a depth varying along the groove length and having respective locations of shallowest depth for said regions, said respective locations being behind said two reversing locations relative to the travel direction of the yarn in the region where the yarn is approaching the respective reversing locations.

2. In a coil winding machine having spool holder means including pivot means for rotatably holding a spool to be wound, the combination with said holder means of a rotatable guiding drum having an axis parallel to that of said pivot means and being, when in operation, peripherally engaged by the spool for driving the latter, said drum having in its peripheral surface a yarn guiding groove extending peripherally and axially of the drum and being closed upon itself, to provide two axially spaced reversing locations for reciprocating the yarn along the spool as the yarn is being wound onto the spool by rotation of said drum, said guiding groove having a depth varying along the groove length and having, in the regions before and behind the reversing locations, respective lo cations of shallowest depth for said regions, said respective locations being behind said two reversing locations, in a region where the groove bottom is touched by the tangent to the running-on surface of the spool which tangent passes in the yarn traveling direction through the outer groove edge of the respective reversing location.

3. In a coil winding machine having means for rotatably holding a spool to be wound, the combination with said holder means of a rotatable guiding drum having an axis parallel to that of said spool and being, when in operation, at least in close propinqnity to the spool,

the spool and drum being rotated at the same peripheral speed, said drum having in its peripheral surface a yarn guiding groove extending peripherally and axially of the drum and having two axially spaced reversing locations, the groove reciprocating the yarn along the spool as the drum is rotated, the yarn being wound onto the spool, said guiding groove having a depth varying along the groove length and having, in the regions before and behind the reversing locations, respective locations of shallowest depth for said regions, said respective locations being behind said two reversing locations relative to the travel direction of the yarn in the region where the yarn is approaching the respective reversing locations.

4. The apparatus defined in claim 3, the said respective locations of shallowest depth being removed a short distance from the respective reversing locations.

5. The apparatus defined in claim 3, the groove bottom having a peak portion behind respective reversing locations, the altitude of the respective peak portion, measured radially, diminishing toward and forward of the respective reversing point.

6. In a coil winding machine for winding yarn onto a takeup spool, a rotatable yarn guiding drum for driving said spool in a single given direction by peripheral contact and having in its peripheral surface a yarn guiding groove extending peripherally and axially of the drum and being closed upon itself to provide two axially spaced reversing locations, the yarn being reciprocated by rotation of said drum, said guiding groove having a depth varying along the groove length and having respective locations of shallow depth behind said two reversing locations relative to the travel direction of the yarn in the region where the yarn is approaching the respective reversing locations, said shallow depth locations being the shallowest of the groove region immediately before and after the respective reversing locations, each of said shallow depth locations being positioned relative to its closest respective reversing location in the travel direction of the yarn so that the yarn is guided by the respective shallow depth location in approximately a straight line therefrom passing through said closest reversing location and tangent to the outer circumference of said takeup spool being wound.

7. The apparatus defined in claim 1, the highest points of the respective groove bottoms for said regions before and behind the reversing locations being at said locations of shallowest depth, a yarn portion being guided from the respective one of said highest points to the runningon point of the yarn at the spool through the radially outermost point of the reversing location, at the groove edge.

8. In a coil winding machine having spool holder means including pivot means for rotatably holding a spool to be wound, the combination with said holder means of a conical rotatable guiding drum having an axis parallel to that of said pivot means and bein wh in operation, peripherally engaged by the spool ro-r dri ing the latter, said drum having in its peripheral sur a yarn guiding groove extending peripherally and of the drum and being closed upon itself and hat axially spaced reversing locations, for recipro yarn along the spool as the yarn is being 2 hind the spool by rotation of said drum, said guiding grcc '2 having in the regions before and behind the 1 locations a depth varying along the groove len having respective locations of shallowest depth regions, said respective locations being behind s reversing locations relative to the travel direc ion of spective reversing locations, the groove bottom 1 peak portions behind respective reversing locations,

,9. In a coil winding machine having spool holder means including pivot means for rotatably holding a spool to be wound, the combination with said holder means of a conical rotatable guiding drum having an axis parallel to that of said pivot means and being, when in operation, peripherally engaged by the spool for driving the latter, said drum having in its peripheral surface a yarn guiding groove extending peripherally and axially of the drum and being closed upon itself and having two axial-1y spaced reversing locations, for reciprocating the yarn along the spool as the yarn is being wound onto the spool by rotation of said drum, said guiding groove having in the regions before and behind the reversing locations a depth varying along the groove length and having respective locations of shallowest depth for said regions, said respective locations being behind said two reversing locations relative to the travel direction of the yarn in the region where the yarn is approaching the respective reversing locations, the groove bottom having peak portions behind respective reversing locations, the altitude of the respective peak portion, measured radial- 1y, diminishing toward and forward of the respective reversing point, said respective locations being in a region where the groove bottom is touched by the tangent to the running-on surface of the spool which tangent passes in the yarn traveling direction through the outer groove edge of the respective reversing location.

References Cited in the file of this patent UNITED STATES PATENTS 1,749,355 Reece Mar. 4, 1930 2,249,147 Kuppers July 15, 1941 FOREIGN PATENTS 683,508 Great Britain Nov. 26, 1952 

